Alzheimer's disease (AD), a type of dementia, is a progressive disease that causes slow decline of the brain's nerve cells involved in learning and short-term memory. That's why memory loss is an early symptom of AD.

"If a person or their family notices new problems with their memory or thinking abilities, or they are displaying a change in behavior or personality, then they should see their primary care physician and ask to be referred to a memory disorders clinic," saysPaul Malloy, PhD, director of psychology at Butler Hospital and co-director of its Memory and Aging Program. "For example, if someone is completely forgetting conversations or significant daily events, this is not normal aging and should be evaluated."

Early intervention is important. "Studies are in progress to identify the earliest signs and symptoms of AD so that treatments can be applied when they are likely to be most effective," Dr. Malloy says. "These treatments may not prevent development of dementia, but they may postpone it and help keep someone functioning well."

The likelihood of onset increases with age. Worldwide, the average lifetime risk of developing any type of AD is about 5% by age 65, 10-15% by age 75, and 20-40% by age 85.

If you have a parent or sibling with AD, your risk doubles. The more affected relatives you have, the greater your risk because you may share certain genes linked to AD.

Common signs and symptoms of AD include:

Memory loss. People with AD are more forgetful, may not remember important dates and repeatedly ask the same questions. Although they may not be able to recall new things, they often remember things from earlier in their life.

Difficulty doing familiar tasks.Routine such as driving to a favorite destination or remembering a game's rules may become difficult.

Trouble solving problems. People with AD may have trouble concentrating, take more time to do things, or lose their aptitude for working with numbers or following a plan.

Bad judgment. Using poor judgment, such as buying into scams, improper self-care, or not seeing a doctor when necessary, are signs of AD.

Easily confused. Someone with AD may not be able to remember the date, where they're going, where they are, or how they got there.

Misplacing things. When someone has advanced AD, they may put things in wrong and inappropriate places, such as jewelry in the freezer. They may not be able to recall where they put something, or think someone stole it.

Problems speaking or writing. Individuals with AD may have trouble coming up with the right word or use a wrong one, making him or her difficult to understand. Their conversation may go off on tangents, they may struggle to follow a conversation, or they may repeat themselves.

Mood changes. Someone with AD can quickly change their mood and be easily irritable, fearful, or depressed.

Personality changes. A person with ADcan easily become upset, especially when they are not in their comfort zone, or they may appear apathetic or indifferent.

Withdrawal from activities. A personwith AD might lose interest in social activities, projects or hobbies.

While AD is not easy to treat, Stephen Salloway, MD, MS, who directs The Memory and Aging Program at Butler, says the answer lies in continued research towards a cure. "The key is to be open-minded, innovative, and persistent. We are making progress," he says.

To learn about Butler Hospital's Memory & Aging Program and current clinical trials for AD being conducted at Butler, visit www.butler.org/memory.